FIG 3.

Replication capacity of HPAI A/H5N1 virus containing substitutions within the receptor binding site. (A) Virus replication on MDCK cells. Virus titers were measured 24 h postinoculation. Mean titers and standard deviations are indicated from two independent replicates. (B) Plaque assays were performed to determine virus replication efficiency in a more sensitive way, with larger plaque sizes corresponding to more efficient virus replication. The plaque radius (in millimeters) is shown. All data measurements are indicated by individual data points. (C) Quantification of virus entry 6 h postinfection by staining intracellular levels of NP. Percentage of positive cells multiplied by mean fluorescence is shown. Mean values and standard deviations are indicated from two independent replicates. ND, not determined.